This invention is generally directed to a novel system that senses the presence of a semi-tractor as the mechanical connection between a trailer and a fifth wheel of the semi-tractor is made, or that senses the presence of a rail car as the mechanical connection between the trailer and a stanchion plate of the rail car is made.
Currently, some prior art systems sense the presence of a trailer when the trailer is connected to a semitractor, but these systems require that an electrical connection or a pneumatic connection be made between the trailer and the semi-tractor. Mechanical switches have been used to sense the presence of an electrical connector, known as the 7-way or J560, or the presence of the pneumatic connectors, commonly known as xe2x80x9cgladhandsxe2x80x9d. Some prior art systems are configured to electrically sense that a trailer is connected to the semi-tractor by sensing the presence of voltage on the J560 connector or in one of the harnesses. Other systems are configured to pneumatically sense that the trailer is connected to the semi-tractor by sensing the presence of air pressure on the braking supply line from the semi-tractor. A pressure switch or transducer has been used to accomplish this pneumatic sensing.
In the prior art, completing an electrical or pneumatic connection between the trailer and the semi-tractor is a secondary operation and may be forgotten by the operator. This can result in an error in the system operationxe2x80x94the trailer is connected to the semi-tractor, but the electrical or pneumatic connection is not made, so the system determines that the trailer is not connected to the semi-tractor.
The present invention senses the presence of the semi-tractor or the rail car without any additional operation. Other features and advantages of the present invention will become apparent upon a reading of the attached specification in combination with a study of the drawings.
The present invention discloses a system for sensing the presence of a semi-tractor as the mechanical connection between a trailer and a fifth wheel of the semi-tractor is made, or for sensing the presence of a rail car as the mechanical connection between the trailer and a stanchion plate of the rail car is made. A sensor is provided in the floor of the trailer proximate to the kingpin. The sensor senses the presence of the fifth wheel or the rail car stanchion plate during the connection process. Control circuitry on the trailer processes and uses signals from the sensor to perform various functions.